英文阅读--20140915NPR

A frame grab from a video released by the Islamic State shows an IS militant holding a knife before purportedly executing British aid worker David Cawthorne Haines.

Islamic State Video/EPA /LANDOV

==>  frame  场景，片段； grab  抓取；  purport  声称，意图

Vowing justice for murdered aid worker David Haines, Britain‘s Prime Minister David Cameron says his killing by extremist group the Islamic State is "an act of pure evil." A video purporting to show Haines‘ beheading was released Saturday.

==>  vow   誓言； grab  抓取；  beheading  斩首，砍头

That video was released on the same weekend that Haines‘ family had publicly asked his captors to contact them. Instead, the group released the video, the third to show a Western hostage being killed in the past month.

==>  captor 逮捕者； hostage 人质

Calling Haines a "British hero" who was an innocent in the fighting that has consumed much of Syria and swaths of Iraq, Cameron said, "We will do everything in our power to hunt down these murderers and ensure they face justice."

Cameron spoke about the killing Sunday, after meeting with his emergency response team at 10 Downing Street.

He pledged to work with Britain‘s allies to destroy the Islamic State, saying of the group‘s members, "They are not Muslims, they are monsters."

==>  pledged  承诺，誓言   

Haines, 44, had spent much of the last 15 years working for relief agencies. Before he was kidnapped in Syria in the spring of 2013, he had worked with the U.N. and several charitable agencies in the Balkans, South Sudan, and Libya. He was also a husband and the father of two daughters, ages 17 and 4.

==>  relief agency  救援机构；   charitable agency  慈善机构  

"David was like so very many of us, just another bloke," his brother, Mike, said in a statement released Saturday, in which he describes how his brother dedicated himself to humanitarian work after leaving Britain‘s Royal Air Force.

==>  bloke  家伙，小子，男人    

As was the case with American journalists James Foley and Steven Sotloff, the video shows Haines wearing an orange shirt, kneeling in a desert alongside a militant who is dressed in black and is armed with a knife.

==>  kneeling  下跪

"My name is David Cawthorne Haines. I would like to declare that I hold you, David Cameron, entirely responsible for my execution," Haines said, according to the BBC.

==>  to hold sb responsible/liable/accountable for   要求某人负责

Haines then said he was being punished for Britain‘s policies.

The BBC reports, "The militant, who appears to have a British accent, is then recorded as saying: ‘This British man has to pay the price for your promise, Cameron, to arm the Peshmerga against the Islamic State.‘"